Manufacture of azo-dyestuffs



Patented Apr, 15, 192 30 untrue stares I nane FATENT eunion,

TEUPOLD @SWALJD, E BASEL, SWITZERLANT), ASSIG-NOR TO THE FIRM ill. JR. GEIG'Y S. A., 035 BASEL, SWITZERLAND.

MANUFACTURE OF AZO-DTESTUJFJFS.

Ito Drawing. Application filed July 14, 1927, Serial No. 2058459, and in Germany July 29, 1926,

Monoazo-dyestufls made from aromatic amines sulphonated in ortho-position are known which have very good properties, such as beauty of tint and satisfactory fastness to light. For instance the dyestulf lake-red C (Schultz, Farbstofitabellen 1914:, No. 153), made by coupling diazotize'd 1-methyl-2- chloro-o-amino-t-benzene sulphonic acid with beta-naphthol, is a Valuable commercial dyestufi.

The dyestufi made by coupling diazotized 2 chloro 5 amino l -sulpho -1 -benzoic acid with beta-naphthol, that is to say a dyestufi difiering from lake-red C in that the carboxyl group is substituted for the methyl group, is not only of purer tint than lake-red C but excels that 'dyestufi in its itastness to light. Similar advantages as compared with dyestufis from non-carbonylated aminoortho-sulphobenzene are to be'oiound in the dyestufi's derived from all amino-sulpho-benzoic acids whether they contain halogen as substituent or not, provided that the aminogroup is in ortho-position to the sulpho-' group.

The invention relates to the manufacture of monoazo-dyestufis by coupling a diazotized aminosulphobenzoic acid in which the sulpho-group is in ortho-position to the aminogroup with a usual coupling component. Of the amino-sulpho-benzoic acids which are used in this invention the valuable monochloro-substitution products have not hitherto been made. 2-chloro-5-amino-d-sulpho-1- benzoic acid can be made by oxidizing the Example 300 litres of a solution containing 25.2 kilos of 2-chloro-5amino-tsulpho-l-henzoic The diazo-compound oi. I

genta' red solution. The calcium or barium lake of this dyestufi has the advantage over lake-red C in that its tint is more fiery and it has a better fastness to light.

The dyestuli may be represented by the following formula:

oooH N I Example 2.

The quantity of diazo-compound made as described in Example 1 is coupled in known manner in solution feebly acid with a min- 'eral acid witl123.9 kilos of 2-amino-8-naphthol-fi-sulphonic acid; when the coupling is complete the whole is made feeblycalkaline with sodium carbonate and the dyestufi' is precipitated in addition of common salt.-,

The dyestu is a dark red powder, easily soluble in water to a dark red solution and. in concentrated sulphuric acid to a dirty Bordeaux'red solution. lit dyes wool in a sulphuric acid bath bluish red, vivid tints or remarkable fastness to light, By afterchroming the tint is only slightly changed, while the iastness is considerably improved.

The dyestufimay following formula:

With the usual pyrazolone derivatives dyestufis are obtained which are characterized be-represented by the by pure greenish yellow to yellow tints of extraordinary fastness to light.

What I claim is:

1. A process for the manufacture of monoazo-dyestufi's, consisting in diazotizing an amino-sulpho-benzoic acid having the sulpho-group in ortho-position to the amino group and coupling the diazo-compound with aryl derivatives having at least one auxochrome group as coupling components.

2. A process for the manufacture of monoazo-dyestufis, consisting in diazotizing a halogen-amino-sulpho-benzoic acid having the sulpho-group in ortho-position to the amino group and coupling the diazo-compound with aryl derivatives having at least one auxochrome. group as coupling components.

3. A process for the manufacture of monoazo-dyestufis, consisting in diazotizing 2- chloro:5-amino-4=-sulpho-l-benzoic' acid and coupling the diazocompound with aryl derivatives having at least one auxochrome group as coupling components.

4., A process for'the manufacture of monoazo-dyestufls, consisting in diazotizing 2- chloro-5-amino-4-sulpho-l-benzoic acid and coupling the diazocompound with 2-amino 8-naphthol-6-sulphonic acid.

5. As new articles of manufacture, the

monoazo-dyestuffs obtained by diazotizing an amino sulpho-benzoic acid having the sulpho-group in ortho. position to the amino group and coupling the diazo-compound with aryl derivatives having at least one auxochrome group as coupling components, and constituting fiery red to dark red powders, soluble in water and concentrated sulphuric acid, yielding vivid dyes of remarkable fastness to light. V t

6. As new articles of manufacture, the monoazo-dyestuits obtained by diazotizing 2-chloro-5-aminol-sulpho-l-benzoic and coupling the 'diazo compound with aryl derivatives having at least one auxochrome' group as coupling components, and constituting fiery red to dark red powders, soluble in water and concentrated sulphuric acid, yielding vivid dyes of remarkable fastness to light,

In witness whereof I have hereunto signed my name this lst day of July, 1927.

LEQPOLD oswanng acid. 

